Method of and apparatus for lapping gears



Dec. 18, 1934. I A. c. PAGE 1,985,213

METHOD OF AND APPARATUS-FOR LPPNG GEARS Filed Sept. 25, 1929 8 Sheets-Shea?l l ATTORNEYS Dec. 18, 1934. A. c, PAGE I METHOD OF AND APPARATUS FOR LAPPING GEARSl Filed Sept. 25, 1929 8 Sheets-Sheet 2 l ATTORNEYS wams A. c. PAGE METHOD OF AND APPARATUS FOR LAPPING GEARS Filed Sept. 25, 1929 8 Sheets-Sheet 5 I vlllnll INVENTOR u- C. lruMA-Twf- ATTORNEYSI Dec. 1s, 1934. A. c.. PAGE 1,9855213 METHOD OF AND APPARATUS FOR LAPPING GEARS Filed sept. 25, 1929 8 sheets-shet 4 ATTOR N EYB Dec. 18, 1934.

zu zog A, c. PAGE METHOD OF AND APPARATUS FOR LAPPING GEARS Filed Sept. 25, 1929 8 Sheets-Sheet 5 INVENTOR @wrm ATTORN EYS De.1s,1934. Y i M; PAGE 1,985,213

METHOD OF AND APPARATUS FOR LAPPING GEARS Filed sept. 25, v1929 s sheets-sheetl 6 ATTORNEYS Dec. 1s, 1934. yA. C. PAGE n 1,985,213

METHOD OF AND APPARATUS FOR LAPPING GEARS CLLdAL C. P04542) ATTORNEYS Dec, 18, 1934. A. c. PAGE 1,985,213

METHOD OF AND APPARATS FOR LAPPING GEARS Filed Sept. 25, 1929 8 Sheets-Sheet 8 INVENTORC 14.5 BY d( j 442:

ovmqmfoy ATTORNEYS Patented Dec. 18, 1934 i UNITED STATES PATENT. OFFICE Alfred C. Page, Detroit, Mich., assignor tol Detroit Trust Company, Detroit, Mich., a corporation of Michigan Application September 25, 1929, Serial No. 394,973 37 claims. (c1. 514-1'51) The present invention relates to a method of and apparatus for lapping gears and embodies improvements over inventions disclosed in Patents No. 1,683,867 and 1,683,868, granted September 11, 1928 to A. W. Coplandand M. I. Mathewson.

The. present invention has for an object to provide a method of grinding gears with laps complemental to the gear, the gear and lap having the form, one of an external gear and the other of an internal gear, complemental thereto in which the necessary pressure between the teeth of the gear and lap .is obtained by yieldably supporting, one for limited movements laterally with respect to the axis of the other, and in which the same relative angular positions are maintained between the teeth of the gear and lap duringtheir engagement.v

The invention also has among its most important objects to simplify the operating mechanism, to provide smoother and more silent operation and to facilitate the adjustment of the machine for operating on diierent gears.

A further object is to provide a simple and r accurate spindle indexing mechanism which operates smoothly and eilciently when the machine is operating at a relatively high speed.

A further object is to provide improved means for starting and stopping the machine, which includes means for stopping the machine only when the spindle is in its uppermost position.

A further object is to provide means in connection with the manually operable clutch controlling means for automatically stopping the machine after a predetermined number of recip- `rocations of the work spindle.

A further object is to provide means for posi- Y tivelyA controlling the movements of the spindle during the lapping operation to maintain the inter-engaging tooth faces of the gear and lap in the correct relative positions.

With the above and other objects in view, the invention may be said to comprise the method and apparatus as illustrated in the accompanying drawings hereinafter described and particularly set forth in the appended claims, together withsuch variations and modifications thereof as will be apparent to one skilled in the art to which the invention appertains.

Reference should be had to the accompanying drawings forming a part of this specification in which:

Figure 1 is a perspective view of the machine.

Fig.v 2 is a fragmentary side elevation of the lower portion of the machine with parts broken away and shown in section.

Fig. 3 is a central vertical section through the upper portion of the machine.

Fig. 4 is a top plan view of the machine.

Fig. 5 is a detail View showing the actuating mechanism for the clamp vwhich engages the spline guide.

Fig. 6 is a plan view of the spline guide clamp.

Fig. 7 is a. transverse vertical section through the upper portion of the machine housing.

Fig. 8 is a fragmentary detail view showing the intermittent worm gearing 'of the indexing mechanism. A

Fig. 9 is a fragmentary vertical section through the main clutch on the crank shaft.

Fig. 10 is a horizontal section taken on the line indicated at 10-10 in Fig. 3, showing the arbor clamp on the work spindle.

Fig. 11 is a section similar to Fig.v 10 showing the clamp in open position.

Fig. 12 is a side elevation of a clutch releasing mechanism mounted 1t one side of the main housing.

Fig. 13 is a section taken on the line indicated at 13-13 in Fig. 12.

Fig. 14 is a fragmentary side elevation showing the clutch holding element released.

Fig. 15 is a fragmentary section takenon the line indicated at 15-15 in Fig. 12.

Fig. 16 is a perspective view showing a device for determining the adjustment of devices for regulating the braking action of the spline guide clamp- Referring to the accompanying drawings, the gear lappingmachine of the present invention has va supporting frame in the form of an upright housing 1 which encloses the operating mechanism of-the machine. The lower portion of the housing has a forward extension 2 which forms a support for a lap table 3 and the upper portion of the housing has a forward extension 4 which f supports a vertical spindle 5 in axial alinement l withthe lap table.

As best shown in Fig. 2 of the drawings, the ylap table 3 is supported upona receptacles which has a cylindrical upper edgeportion '7 upon which the table is mounted. The receptacle 6 is mounted in a circular opening 8 in the top of the forwardly extending portion 2 of the housing and is provided with an'annular shoulder 9 resting upon the top of the housing around the opening.

The receptacle is provided above the shoulder 9 with a circumferential outwardly inclined flange 10 forming an annular trough 11 around the exteriorof the receptacle. Openings 12 are formed in the wall of the receptacle to allow liquid to drain from the trough 11 into the interior of the receptacle. The lap supporting table is of annular form having a central opening 13 of a diameter slightly less than the internal diameter on recep- .tacle 6, and is provided with an annular groove 14 in the bottom thereof which receives the upper edge of the receptacle and a wenn gear 15 attached to said edge, the worm gear being of annudiameter as the internal diameter of the receptacle 6. The table 34 has a flange 16 between the groove 14 and central opening thereof which bearsv 1 the exterior ofthe receptacle below the worm gear.

Mounted in the table 3, there is a worm 19 which meshes with the worm gear 15, the worm being mounted upon a shaft 20 journaled in the lap table which is provided with a skirt 22 overlying the worm 19. The shaft 20 projects through the skirt 22 and has a hand wheel 23 fixed thereto outside the skirt. By turning the handwheel 23,

the lap table may be adjusted angularly on itssupport, 'the table being locked in adjusted position by engagement of the worm 19 with the worm gear 15. l

At the top thereof, the table 3 is provided with an annular recess 24 at the margin of the central opening and in this recess, there is mounted a removable ring 25 which is detachably held in place by clamping lugs 26 which engage the top of the ring 25 and are clamped to the top of the table by means of bolts 27. The removable ring 25 serves as a support for a lap 28 such as shown in Fig. 2,

which is in the form of an elongated internal gear.

complement-al tc the gear to be lapped. The lap 28 has a cylindrical external surface and is provided with an external circumferential rib 29 midway between the ends thereof. The diameter of the lap employed will vary in accordance with the size of the gears to be lapped and a removable ring 25 will be provided for each size of lap. The ring for each lap has a central opening of a diameter such that the lap will have a close t therein, the lap being supported on its projecting rib 29 which rests upon the tcp surface of the ring 25. The lap is preferably rigidly secured to the ring 25 by means of clamping-lugs 30 which engage the upper side 'of the rib 29 and are clamped to the top o'f the ring 25 by bolts 31.

During the lapping operation, asuitable liquid such as kerosene' carrying nely divided abrasive material in suspension therein is pumped from a suitable reservoir 32 within the housing adjacent ,the base thereof by means of a suitable pump` 33 driven by an electric motor 34 through a discharge pipe 35 :int'b the interior of the lap. The upper end of the discharge pipe 35 is adjustably supported upon a bracket 36 which is mounted for vertical adjustment on a vertical guide rod 37 carried by brackets 38 and 39 attached vto the side of the housing 1. The discharge pipe 35 is provided with a downwardly directed discharge nozzle 40 at its upper end and with a hand valve 4l by means of which the ilow of liquid and abrasive may be stopped when desired. The lower end of the receptacle 6 is connected by a. return pipe- 42 with the reservoir 32 so that the liquid and abrasive material, after .passing through the lap is returned to the reservoir.

To direct the liquid and abrasive material from the nozzle 40 into the interior of the lap, a funnel composed of upper and lower sections 43 and 44 is mounted upon the upper end or` the lap 28. The upper section 43 of the funnel has into the funnel is directed to the interior of the lap.

A lower funnelsection 44 is provided for each size of lap and each of these funnel sections has a lower end portion 46 of a diameter to fit a gear lap and all of these funnel sections have an upper end portion of a diameter to fit within the lower portion of theupper section 43 of the funnel so that when a lap of diierent diameter is mounted in the lap table, it is necessary only to replace the lower section of the funnel.

Gears to be lapped are detachably supported upon the lower end of the spindle 5 and the spindle is mounted to reciprocate vertically to move the gear downwardly and upwardly through the lap upon each stroke of the spindle.

To detachablyv mount the gear upon the lower end of the spindle 5, the lower end vof the spindle has detachably secured thereon a sleeve 47 which is held against rotation on the spindle by means ofl a spline 48 and which is clamped against the under side of a circumferential rib 49 on the spindle by means of an internally threaded coupling member 50 which screws upon the upperv end of the sleeve 47 which is externally threaded, the coupling member having a close fit on the spindle above the rib 49 so that when the coupling member'is screwed tight on the sleeve 47, the sleeve is clamped tightly against the under side of the rib 49. The sleeve 47 has an integral extension 52 extending downwardly therefrom at one side, and detachably secured to the extension 52, there is a V-shaped saddle 53. An arched clamping bar 54 is pivoted to one side o f the extension 52 and this clamping bar is provided with a handle 55 and with a spring actuated hand latch 56 which engages with a keeper 57 carried by the extension 52 at the edge thereof opposite that to which the clamping bar is hinged.

Midway between the ends thereof, the/clamping bar carries a spring pressed pin 58, whichV at its upper end against which a gear -64 may be clamped by means of a nut 65 on the lower end of the arbor. The arbor is also provided with be lapped may be rigidly clamped upon the'lower lend of the arbor. The arbor 59 is rigidly held against rotative movement with respect to the spindle 5 by the pin 60 engaging in the socket 6l, The arbor, however, has lateral play between the inner surface of the clamping bar 54 and the V-shaped saddle 53, the arbor being yieldingly held against the inclined surfaces of the saddle by the spring pressed plunger 58. The lateral play of the arbor with respect to the spindle is advantageous in that it permits the gear to have the lateral movements necessary to accommodate it to the lap when the lap is slightly eccentric with respect to the spindle axis. It has been found advantageous in the nlshing of some gears to 4mount the lap slightly eccentric with respect to the spindle, since by so mounting the lap, a greater crowning eiect is produced on the gear teeth.

The spindle 5, as best shown in Fig. 3 of the drawings, s rotatably mounted in'an elongated sleeve 68 which is mounted to slide in a vertically disposed bearing 69 formed in the forwardly extending portion 4 of the housing. The sleeve 68 is held against turning movements in the bearing 69 by means of a spline 70 and has a rack 71 formed along the inner side thereof whichis engaged by a gear segment 'i2 which engages the rack through a vertical slot 73 on the inner side of the bearing 69, the gear segment being oscillated by a Vmechanism which will be hereinafter described to impart a reciprocating movement to the sleeve and spindle. The spindle 5 is held against longitudinal movement in the sleeve 68 by means of ball thrust bearings 74 and 75 above and below a threaded plug 746 screwed into the upper end of the sleeve 68. The upper bearing 74 is clamped against the top of the plug 76 by a nut 77 screwed on the spindle 5 and the lower bearing 75 is clamped between the threaded plug '16 andl a shoulder 78 on the spindle 5.

The spindle 5 is provided with a tapered upper end 79 to which there is detachably secured a spline extension 80 which has a tapering socket 81 at its lower end in which the tapering upper end of the spindle fits, the extension being rigidly secured to the spindle by means of a bolt 82 which extends axially through the extension and screws into the upper end of the spindle. The spline extension passes through a spline guide l 83 which is detachably secured by means of bolts 84 to a supporting vmember 85 which has a-.depending sleeve portion 86 which forms a bearing for .the lower end portion of the spline extension and which extends through a bearing boss 8'? formed integrally with the top wall of the housing 1.

During the portion of each reciprocating stroke of the spindle in which the gear 64 is within the lap 28, the spline guide 83 is rigidly held against rotative movement and the spindle during the reciprocating stroke has only such rotative movements as may be imparted to it by the spline guide. If a spur gear is being lapped, the spline extension will have straight axially extending ribs and the spline guide will have straight vertical grooves to receive the `ribsand there will be no rotative movement of the spindle.

- Both the spline extension and spline guide may be quickly and' 'easily removed and replaced. When helical gears. are being lapped, it is necessary that the spindle have a turning movement as it is moved longitudinally to enable the teeth of the gear to follow the helical teeth of the lap as the gear is moved through the lap, and for a gear of any given helix angle, there will be provided a spline extension and complemental spline guide having helical ribs and grooves of the proper inclination to impart to the spindle rotative movements exactly corresponding to the rotative movements which would be imparted to the spindle by the helical gear in its axial reciprocating movements through the complemental lap, so that the teeth of the gear are automatically guided through the grooves of the lap during lapping operation by means other than the lap itself. A

The machine is driven through a flywheel pulley 88 `which has suilicient weight to substantially equalize the driving thrust and. eliminate the periodic increases in torque at the ends vof the stroke of the spindle. The pulley 88 is adapted to receive a driving belt extending from a suitable drive shaft and is fixed to a horizontal shaft 89 extending through the housing and :journaled in a bearing bracket 90 fixed to one sidewall of the housing and in a suitable b/earing in the opposite sidewall. Rotatably mounted on the shaft 89, there isa gear 91 which has a clutch element 92 formed integrally therewith, the clutch element having an inwardly tapering internally conical friction surface which isengaged by the conical periphery of a shiftable clutch member 93 splined on theshaft 89, by means of a pin 94 passing.

through a slot in the shaft. The shiftable clutch element 93 is held in engagement with th'e clutch member 92 of the gear by means of a-push rod 95 extending axially through the shaft 89 from the outer end thereof. .The outer end of the push rod 95 is engaged by a plug 96 screwed into the outer end of the shaft and adjustable axially to regulate the pressure with which the clutch member 93 is held against the clutch member 92. The clutch connection between the gear 91 and shaft 89 provides a frictional slip connection between the gear and the shaft so that if, for any reason, an excessive torsional thrust is imposed upon the driving shaft, the clutch will slip. For instance, the lap might be so mounted that the grooves thereof will be misalined with respect to the teeth of the gear carried by the spindle so that, when the spindle is moved downwardly, the teeth of the gear will strike the ends of the lap teeth,'in which case the friction clutch would slip and prevent damage to the spindle actuating mechanism. 4,

The gear 91 meshes with a gear 97 which is xed to a sleeve 98 rotatably mounted on a transverse shaft 99 parallel with theshaft 89 and directly .above the same, the shaft 99 being journaled in ball bearings 100 mounted in the bracket 90 and in the opposite wall of the housing, respectively. As best shown in Figs. 7 and 9, the sleeve 98 carries aclutch member 101 at its outer end, which has an internal cylindrical surface engaged by an expanding clutch band 102 carried by a sleeve 103 xed to the shaft 99 and having lingers 104 which are engaged by a wedge 105 carried by a shiftable clutch member 106 splined on the sleeve 103. The shiftable clutch element 106 is actuated by a forked shifter lever 107 which is pivoted intermediate its ends to the bracket 90.

The'shaft'99 is provided with a crank 108 within thehousing 1, and this 'crank is connected by a connecting rod 109 with the gear segment 72,

l driving connection between the shaft 89 and shaft 99 may be broken and the reciprocation of the spindle-may be stopped. The eccentric shaft 111 may be adjusted angularly in the varm to adjust the gear segment toward fand away from the 'spindle 5 to provide. the proper meshing engagement between the teeth of the gear segment and the teeth of the rack 71.

Since, in the operation of the machine, the machine is ordinarily stopped to permit the replacement of one arborI and attached gear by another, it is desirable that the machine be always stopped with the spindle. 5 in its uppermost position, in-

prevent movement of the shiftable clutci.. member 106 to releasing position at any time other than that at which the spindle is in its uppermost position, the clutch member 106 carries a cam 106e in the form of an external sleeve, the outer edge of which is engaged by a roller 112 carried by a vertical shaft 112a xed to a bracket 113 attached to the housing 1 above the shaft 99.

At one point in its circumference, the outer edge of the cam sleeve 10Go is provided with a recess 114 into which the roller 112 is adapted to enter, permitting the outward movement of the clutch member 106 when the recess 114 is opposite the roller 112, the recess 114 being' alined with the crank pin to which the connecting rod 109 is attached, so that the releasing movement of the clutch member must always occur when the spin dle is in its uppermost position.

In order to absorb the momentum of the moving parts of the machine and to bring the spindle quickly to a stop without undue strain o the actuating members, the shiftable clutch member 106 has a conical brake member 115 at its outer end which engages the internal conical surface of a brake member 116 iixed to the housing l so that when the clutch is released, the brake is automatically applied to stop rotation of the crank shaft 99.

The weight ofthe spindle 5 and attached parts is partially counterbalanced by a spring 117 exerting its thrust upon the segment arm 110 in an upward direction. The spring 117 is mounted upon a rod 118 which has its upper end slidable in a rotatably mounted guide member 119 carried by the segment arm and its lower end resting in a recess in the upper face of a bracket 120 the guide member 119, and the lower washer held by nuts 122 screwed onto the lower end portion of the rod 118. v

In addition to operating the crank shaft 99 through the gears 91 and 97, the drive pulley 88 also actuates indexing mechanism which automatically imparts a turning movement to the.

` ing the portion of each stroke in which the gear is outside the lap. The indexing mechanism is operated by intermittent worm gearing consisting of a worm 123 fixed to the shaft 99 and having a threadV 124 which has portions of circular form extending circumferentially in planes perpendicular to the axis of the worm throughout the major portion of the circumference thereof and which has helical portions 125 joining adjacent straight circumferential portions, the thread consisting of axially spaced portions of circular form lyin'g in planes perpendicular to the axis and each extending .throughout more than half the circumference of the worm and helical portions 125 joining adjacent axially spaced circumferential portions.

The worm 123 meshes with a composite gear 126 which has composite spur and helical teeth, each tooth having parallel axially straight face portions 127 and parallel helical face portionsl the worm. The helical gear is then cut with a hob set to generate a spur gear having teeth formed to mesh with the straight portions of the worm threads. The second hob cuts away end portionsy of the faces of the helical teeth and provides the straight spur tooth faces 127 at opposite ends of each tooth. The teeth of the worm 123 are so designed that the gear 126 is turned one tooth space by the helical lportions 125 of the worm at each revolution of the worm. The helical portions 125 of the worm threads impart a movement to the gear 126 during the portion of the revolution of the worm in which the helical portions 125 of the worm threads engage the helical faces 128 of the gear 126 and the straight portions of the worm thread engaging the straight portions 127 of the gear teeth lock the gear 126 against turning movement during themajor portion of the revolution of the worm. The helical portions 125 of the Worm thread are so disposed with respect to the crank 108 that the turning movement is imparted to the gear 126 while the spindle is at one end of its stroke with the gear out of engagement with the lap.

The gear 126 is fixed to the lower end of a vertical shaft 130 which is journaled in an elongated bearing member 131 which is detachably mounted in the top wall of the housing 1. At its upper end, the shaft 130 has xed thereto a gear 132 which has the same number of teeth as the worm gear 126. A radially extending arm 133 is mounted for angular adjustment on the bearing member 131 immediately beneath the gear 132, the arm 133 pivoting about the axis of the shaft 130. A gear 134 having any convenient number of teeth is mounted upon the outer end of the arm 133 and meshes with the gear 132.

The gear 134 meshes with a change gear 135 which is detachably secured upon the upper end of a vertical shaft 136 and which has the same number of teeth as the gear 64, whichV is being lapped. The gear 135 can readily be removed from the shaft 136 and replaced' with a gear' having a diiferent number of teeth corresponding to that of another gear to be lapped, the angular adjustment of the arm 133 permitting the gear 134 to be moved to a position in which it will properly mesh with the gears 132 and 135. The vertical shaft 136 extends down into the housing 1 and has iixed to its lower end a gear 137 provided with any convenient number of teeth and this gear meshes with the gear 138 y During the operation of the machine, the worm 123 turns the gear 126 through one tooth space for each revolution of the crank shaft 99, the turning movement being imparted to the gear 126 during the portion of the revolution of the crank shaft, at which the spindle 51s in its uppermost position.

The gear 132 having the same number of teeth as the gear 126 is also turned through one tooth rspace, turning the gear 134 one tooth space and the gear 135 one tooth space through the gear 134. The angular movement imparted to the vertical shaft 136 is equal to one tooth space of the gear being lapped, since the gear 135 has the same number of teeth as the gear being lapped and the angular movement imparted to the spindle 5 .through Ythe spline guide 83 is exactly the same as the angular movement of the shaft 136, since the gears 137 and 138 have an equal` number ofteeth.

15 by a bolt 142.

There is necessarily a certain amount of backlash in the gearing between the worm 123 and the spline guide 83 which normally would permit the spindle to have a slight amount of angular 5 play during its engagement with the lap. It is desirable, however, that the spindle be positively held against angular movement except during the indexing operation and to this end, as best shown in Figs. 4 and 5, a clamp 139 in the form of a split collar is secured to the top of the housing by a bolt 140 and extends around the spline guide 83 in clamping relation thereto, the \ends of the split collar are in the form of outwardly extending anges 141 which are connected One end of the bolt extends through the end of an angle shaped lever 143, which extends across the ends of the flanges 141 and has an end portion 144 at right angles to the body portion of the lever and interposed be;

2O tween the outer face of one of the flanges -141 and a nut 145 on the bolt 142.

As shown inFig. 6, the aperture in the end portion 144 of the lever through which the bolt 142 extids is of a diameter slightly greater than 25. that-of the bolt so that the lever can rock about the inner corner of the end portion 144 as a fulcrum, outward movement of the lever serving to draw the ends of the clamp 139 together to frictionally grip the spline guide 83 and posi-v tively hold the same against turning movements.

In the outer end of the lever 143, there is mounted a tubular socket 146 which receives the reduced end 147 of an actuating push rod 148. The opposite end of the rod 148 is plvoted to the upper end of a lever 149, see Figs. 1 and 5, which is pivoted intermediate its ends to the housing at 150 and carries a roller 151 at its lower end which engages with a cam 152 fixed to the end of the crank shaft 99. 'I'he cam 152 has a low 40 portion 153 which is so positioned with respect to the crank that the outward pressure on the rod 148 is relieved during the portion of the stroke of the spindle in which the indexing operation takes place. Within the tubular socket 146, there is mounted a coil spring .154 which is interposed between the reduced end 147 of the rod and a screw 155 mounted in the opposite end of the socket and alined with the rod. The actuating rod 148 is so positioned with respect to the lever 143 that when the. roller 151 engages the low portion of the cam 152, the shoulder at the inner end of the reduced end 147 of the rod is out of contact with the end of the socket 146 and the only pressure exerted upon the lever 143 is that exerted by the spring 154, the tension of which collar 139 is held tightly against the spline guide 83 to positively hold the same-against turning movement. Inasmuch as the operation of the machine is quite rapid, the momentum of moving parts would at times tend to throw the spindle ahead of the gearing by which it is operated during the indexing operation and the backlash of the gearing in the indexing train would permit variations in the angular movements of the spindle in successive indexing operations. To prevent this variation in the indexing movement, the

pressure of thel lever 149 on the rod 148 is released but The spring 154 causes the clamping collar 139' to frictionally engage the spline guide during the indexing operation to impose a load on :5 the gearing between the worm 123 and the spline guide which will maintain the gear teeth in contact and prevent the spline guide from movingl ahead of the gearing which drives it so that exactly the same angular movement is imparted to the spline guide during each indexing operation. Driving pressure is thus lmaintained between the teeth of the gears in the gear train of the indexing mechanism, so that there can be no variation in the angular indexing movement due to backlash in the gearing of the gear train.

In order to obtain the proper adjustment of the'clamping collar 139 on the spline guide 83, the nut 142 is adjusted with the push rod 148 disconnected from the lever, 143 to tighten the collar 139 on the spline guide 83 just enoughl to bring the collar into contact with the cylindrical surface of the spline guide, but not enough to` cause the collar to exert a clamping action on the spline guide.

The screw 155 should be adjusted-to put the spring 154 under the proper tension each time a different change gear is substituted in the indexing gear train in order that the spring 154 may exert the amount of pressure on the lever 143 during the indexing operation necessary to prevent play between the gears of the indexing gear train.

To accurately determine the adjustment of the screw 155 to accomplish this result, a scriber 156 may be mounted on a post 157 secured to the top of the housing 1 alongside the spline guide 83, as shown in Fig. 16, the scriber being pivoted to swing about a pivot 158 adjacent the top of the post so as to make marks across the cylindrical edge 159 of the flange ofthe spline guide 83.

After a new change gear has been put in place in the gear train, the screw 155 is adjusted to release the tension of the spring 154 and the pulley 88 is slowly rotated by hand. Marks are then made by the scriber 156 on the cylindrical surface 159 of the spline guide upon each stroke of the spindle and while the spindle is in the lower portion of its stroke and the spline guide is stationary. The machine is then run under power and the screw 155 is adjusted until the marks on the surface 159 coincide with the point of the scriber after each indexing movement,

whereupon the screw 155 is locked in adjusted` or closure member 161 so that any of the parts vcan be readily detached and removed through the opening in the housing, the parts within the housing being introduced into 'the housing through the opening in the rear wall therein and assembled within the housing in the manufacture of the machine.

The lower end of the clutch lever 107 is pivotally connected to the end of ahorizontally'disposed rack bar 162 which extends transversely through the housing 1 and is slidably mounted in the side walls thereof. A yielding thrust is exerted on the rack bar 162 tending to move the same in a direction to shift the lever 107 to clutch disengaging position by means of a compression coil spring 163v on the rod interposed between the side wall adjacent the lever and a collar 164 on the rack bar. The rack b ar 162 projects through the side wall of the`housing 'oppositethat upon which the lever 107 is mounted and has rack teeth 165 formed on the end thereof projecting through the side wall which mesh with a pinion 166 mounted exteriorly of the housing 1. The pinion 166 and the projecting end of the rack bar 162 are within a housing 167 mounted on the side wall of the main housing l. This housing has an outer wall in the form of a door 168 which has a bulged portion 169 providing a recess for the projecting end of the rack bar 162. The pinion 166 meshes with a vertically disposed rack bar 170 which projects downwardly through the bottom wall of the housing 167 and along the side wall of the housing 1 being slidably mounted at its lower end in a bearlng member 171 mounted'on main frame. The vertical rack 170 may be manually actuated by means of a hand lever 173 which has a forked end 174 which straddles the rack bar above the collar 172.

The lever 173 which is pivoted to the housing intermediate its ends may be actuated to swing the forked end 171i thereof downwardly against the collar 172, moving the rack 170 downwardly and thereby rotating the pinion 166 in a direction to move the rack bar 162 toward the lever 167 `to shift the lever in a direction to clutch the sleeve 98 to the crank shaft 99.

The clutch lever 107 is retained in clutch engaging position after it has been moved to this position by the lever 178 by means of combined latch and trip members 175 which engage the rack bar 162 to retain the same in the position in which the driving clutch is held in engagement. Two identical latch and trip members 175 are provided and these members are mounted on a fixed pivot 176 within the housing 167. Each of the trip members has a latch arm 177 which projects over the top of the rack bar 162 for engagement with inner and outer shoulders 178 and 179 formed in a spline 186 extending along 106a and roller 112.

the top of the rack bar 162.

Each of the trip members has an actuating arm 181 on the side of the pivot opposite the latch arms 177 and each of these actuating arms is engaged by a spring pressed plunger 182 which exerts itspressure on the arm in a direction to move the latch arm of the trip member 177 into locking position. The two trip members also so that when the push rod is shoved rearwardly,

both latch arms are simultaneously lifted out of engaging position so that the rack bar 162 may be shifted by the spring 163 in a direction to re lease the clutch. The shiftable clutch member 106, however, will be prevented from -moving voutwardly to releasing position until the spindle 5 is at the upper end of the stroke by the cam In the operation of the machine, it is desirable to reciprocate the gear being lapped through the lap a predetermined number of times so that the desired abrading action on the teeth of the gear may be obtained and in the machine of the present invention, means is provided for automatically actuating the trip members after a predetermined number of revolutions of the crank shaft. The members 175 are tripped by means of a worm gear 186 mounted on a horizontal shaft 187 above the actuating arms 181 of the trip members, the lower portion of the gear lying between the arms 181 and the gear being provided on the opposite side faces thereof with projecting pins 188 and 189 which are spaced angularly a short distance for apurpose which will presently be explained. Each of the arms 181 is provided with a cam projection 190 on the upper side thereof and these projections are engaged by the pins 188 and 189 to force the. arms 181 downwardly and lift the arms 177 clear of the shoulders 178 and 179. The pin 188 engages the cam projection 190 of the inner of the two trip members before the pin 189 engages the cam projection 190 of the outer of the trip members so that the pin 188 moves past the projection.190 of the inner ,trip member releasing the inner trip member before the outer of the trip members is actuated. l

As best shown in Fig. 15 of the drawings, the distance between the shoulders 178 and 179 is slightly less than that between the inner engaging faces of the latch arms 177, so that when the inner latch arm 177 engages the shoulder 178/the shoulder 179 is spaced inwardly a short distance away from the outer latch arm. y

The release of the inner latch arm permits the rack bar 162 to move outwardly until the shoulder 179 engages the latch arm. 177 of the outer trip member. 'I'his outward movement of the rack bar, however, is not sumcient to release the clutch-but positions the shoulder 178 otwardly of the inner engaging face of the inner latch arm 177, so that, when this arm is released, it will rest on the upper edge of the spline permitting the rack bar 162 to be moved outwardly by the spring 163 when the outer latch arm 177 is released. j

If a single trip member were provided, the machine might be stopped 'with the actuating pin on top of the cam projection so that the latch arm would be held by the pin in elevated position out of thepath of the shoulder on the rack bar after the machine has been stopped, and it would then be necessary for the operator to hold the rackbar 170 in its lowermost position by means of the lever 173- until the machine had operated long enough' to move the pin 189 clear of the projection190. This would be inconvenient, since the rotation of the worm gear 186 is necessarily quite slow. The diiliculty above pointed out is avoided by providing the trip mechanism above described having the pair vof identical -trip members and the angularly' spaced pins on the worm gear. g

The worm gear 186 is driven by a worm 191 fixed to a vertical shaft 192, which is'drlven through a helical gear 193 rotatably mounted lon the shaft and meshing with a helical 'gearl 194 fixed to a horizontal shaft'195. The helical` gear 193 carries a clutch element 196 which cooperates with a shiftable clutch element 197 splined to the shaft 192 and serving to establish a, driving connection between the helical gear 193 and the shaft. The shiftable clutch element 197 is yieldingly pressed toward engaging position by means of a compression coitspring 198 and may be shifted to releasing position by means oi' a lever 199 which is pivoted intermediate its ends to the housing and connected at its outer end and by a link 200 to a second lever 201 pivoted intermediate its ends at 202 and having its free end directly overlyingthe upper end of the'rack 170 so that when the rack 170 ismoved upwardly on release of the latches holding the rack bar 162, the rack 170 engages the lever 201 and moves the same in a direction to release the clutch elementvlQ-S so that the rotation of the trip actuating Worm gear 186 is automatically stopped upon the release of the crank shaft clutch.

The horizontal shaft 195 has nxed thereto a pinion 203 which meshes with a gear 204 on the stub shaft 205 at the outer end of an arm 206 carried by a collar 207 which is rotatably mounted on a bushing'208, which forms a bearing for the end of the shaft 89 opposite that to which the drive pulley 88 is connected. 'I'he collar 207 has a ange 209 which closely overlies the outer face of the side wall of the housing v1 and this flange is provided with an arcuate slot 210 which receives a clamping bolt 211 which is screwed into a threaded opening in the housing wall and serves to rigidly clamp the collar and the gear carrying arm 206 in various positions of angular adjustment. The gear 204 is driven by a small gear 212 fixed to the end of the shaft 89. The gears 204 and 212 are change gears being readily remov` able and replaceable by gears of different sizes, the adjustment of the arm 206 enabling the gear carried by the arm to have proper meshing engagement with the gear 203. The change lgears permit the machine to be set for any desired number of reciprocations before the automatic releasing mechanism disengages the clutch. In the operation of the machine, the operator, each time the machine stops, removes the arbor and gear at` tached to the spindle, attaches another arbor having another gear thereon to the spindle and restarts the machine by actuating the lever 173. While the machine is operating on one gear, the operator attaches another gear to an arbor ready for attachment to the spindle as soon as the lapping operation upon the first gear is completed.

In order that the teeth of successive gears may accurately aline with the grooves of the lap, it is necessary that the gears all be accurately positioned on the arbor so that every gear is in exactly the same angular position with respect to the pin 60 on the arbor. To enable the operator to quickly and easily position the successive gears on the arbors, a bench 213 is provided at one side of the machine and this bench is provided with a vertical rib which has a V-notch 215 to receive an arbor which is held therein by a clamp 216 having an arbor engagingscrew 216a, a'socket 217 beingprovided to receive the pin 60 of the arbor 59`in the fixed jaw. An arm 219 is mounted on the bench at one side of the notch 215 to swing on a pivot 220 and this arm carries a gear 221 which is rigidly and non-rotatably attached to the arm and has teeth formed to mesh with the gear to be lapped. If the gear to be lapped is a spur gear, the gear 221 will be a spur gear adapted to mesh therewith and if the gear to be lapped is avhelical gear, the gear 221 will be a helical gear con jugate to the gear to be lapped.

When the lapping operation is started on a series of identical gears, an arbor with a gear attached thereto in the position determined by the gear 221 is attached to the spindle and the lap table is carefully adjusted by means of the worm 19 to theposition in which it alines with the gear. Gears subsequently mounted on the spindle having been positioned on the arbor by the gear 221 will, when the arbor is attached to the spindle, be properly alined with the lap.

In setting the machine for lapping a given gear, a spline extension having splines disposed at the proper helix angle is attached to the upper ing the indexing movement to prevent play be- 'f tween the gears of the indexing train, as will be indicated by the scriber and marks on the cylindrical surface of the spline guide, as above explained. A gear is then put on an arbor held in the clamp 216, is positioned on the arbor by means of the gear 2,21 and is then clamped in place on thearbor. The arbor with the gear thereon is secured to the spindle 5 and the lap table 3, (in which a lap conforming to the gear to be lapped has been secured) is adjusted angularly by means of the worm 19 until the teeth of the gear register with the grooves of the lap.

l The machine is started into operation by lifting the hand lever 173 to depress the rack bar 170 and actuate the rack bar 162 through the pinion 166 against the action of the spring 163 in-a direction to engage the crank shaft clutch, the rack bar 162 being held in yretracted position by the latch arm 177 engaging the shoulder 178 on the rack bar.

As the crank shaft 99 is rotated, the spindle 5 is reciprocated vertically causing'the gear to pass downwardly and then upwardly through the lap, the Agear being held with its teeth in a predetermined angular relationship to the teeth of the lap during the reciprocating movement by the spline extension of the spindle and the spline guide through which it passes. At the upper end of each stroke of the spindle, the spindle is indexed one tooth space by the helical portions of the teeth of the worm 123. Each revolution of the drive shaft 89 turns the worm gear 186 through a small angle through the gearing shown in Fig.,12 and, after a predetermined number of reciprocations, the trip pins 188 and 189 on the Worm gear 186 will release the rack bar 162 and permit the spring 163,y to release the crank shaft clutch when the recess 114 of the cam 106a registers with the roller 112, stopping the gear carrying spindle in its uppermost position. While one gear is being lapped, the operator assembles a second gear on an arbor on the bench 213, as above described, replacing the gear and arbor on the spindle with a second gear and arbor. Since every gear' is positioned exactly the same with respect to the pin 6070i the arbor by means of the gear 221 on the work bench, each gear will beVA properly alined with the lap.

The position of the gear on the spindle is such that continuations of the teeth of the gear pass through the grooves of the lap in intermeshing relation with the teeth of the lap and the `pitch or angularity of the splines on the spline extension 80 and spline guide 83 is such as to hold the tooth faces of the gear in the extensions of the curved surfaces of said faces, i. e., in the same relative angular positions with respect to the vtooth surfaces of the lap, while the gear is passing through the lap. The automatically actuated clamping collar 139 positively holds the spline guide 83 against turning movement during engagement of the gear with the lap so that the gear, which is keyed to the spindle, is positively held against angular movements about its axis, which would change the relative angular positions of the gear and lap tooth faces. The arbor 59, however, is so mounted in the spindle clamp that it.A may have slight movements laterally of the axis of the spindle, such movements being opposed by the spring plunger 58. The lateral yielding of the arbor permits a slight lateral shifting of the gear in the lap sumcient to permit the gear to accommodate itself to the lap. ln the cycle of operations above described, each tooth of the gear engages succes'- sively each tooth of the lap, irregularities and inaccuracies in tooth face contour are gradually eliminated, and the teeth become accurately spaced, the method of the present invention serving to finish the teeth of gears with remarkable uniformity in tooth contour and tooth spacing.

When an appreciable crowning effect on l.the gear teeth is desired, the lap may be positioned slightly eccentric with respect to the spindle axis, in which case the abrading effect on the ends of the gear teeth is greater than when the lap and spindle are in exact axial alinement causing the end portions of the tooth faces to be ground away to a greater extent than the central portions thereof.

As herein illustrated, the abrading action is obtained by abrasive particles fed between the interengaging tooth faces of the gear and lap, but it is to be understood that the lap may be in the form of ahome with abrasive particles embedded therein, as shown in my copending application Serial No. 352,336, iiled April d, 1929. Furthermore, the method of the present invention may be employed for iinishing internal gears, as well as external gears in which case the lap has the form of an external gear complemental to the internal gear to be finished.

ln addition, the lap, when desired, may be mounted on the reciprocating spindle and ,the gear on the fixed support.

It will be apparent that the present invention provides a very simple `and effective means of maintaining an effective pressure between the interengaging tooth faces of the gear and lap while accurately holding the teeth of the gear and lap in the correct relative angular positions during their engagement.

It will further be apparent that the present invention provides a very simple and accurate indexing mechanism having no parts liable to get out of adjustment or out of order.

It should also be noted that the'. control of the machine is largely automatic so that the operator is required only to replace the arbor and' gear on the spindle with another arbor and gear when the machine stops, and then restart the machine.

Again, it should be noted that the mechanism is so designed that the machine may operate rapidly without appreciable vibration and without aiecting the accuracy of indexing or'of the turning movements of the spindle during the lapping action. ,Y

Furthermore, it is to be understood that the particular form of apparatus shown and described, and the particular procedure set forth,

lare presented for purposes of explanation and illustration and that various modifications of said 'apparatus and procedure can be'4 made without departing from my invention, as dened in the appended'claims.

What I claim is:

1. A gear lapping -machine comprising a housing, a spindle mounted in the housingV to reciprocate axially, a support, a. lap for engagement with lthe gear to` .be lapped-said gearand menare lap being, one in the form of an external gear and the other in the form of an internal gear complemental to the external gear, one attached to the spindle and the other secured to the support and positively held against turning movements substantially in axial alinement with the spindle, means for reciprocating the spindle to engage and disengage the gear and lap, a spline carried by the spindle, a spline guide rotatably mounted in the housing through which said spline passes, means for holding said spline guide against turning movements during the portion of the stroke of the spindle in which the gear and lap are in engagement and for releasing said holding means while the gear and lap are out of engagement, and means for imparting a predetermined angular movement to the spline guide and spindle while said holding means is jvreleased'.

spline carried by the spindle, a spline guiderotatably mounted in the housing through which said spline passes, means controlled by the spindle actuating means for holding said spline guide against turning movement during the portion of the stroke of the spindle in which the gear and lap are in engagement and for releasing the spline guide during the portion of the stroke in which the gear and lap are disengaged, and means for indexing the spindle while the spline guide is released.

` 3. A gear lapping machine comprising housing, a spindle mounted in the housing to reciprocate axially, a support, a lap for engagement with the gear to be lapped, said gear and lap being, one in the form of an external gear and the other inthe form of an internal gear complemental to the external gear, one attached to the spindle and the other secured to the support and positively held against turning movements substantially in axial alinement with the spindle, means for reciprocating the spindle to engage and disengage the gear and lap, a spline carried by the spindle, a spline guide rotatably mounted in the housing through which said spline passes, means controlled by the spindle .actuating means for holding said spline guide against turning movement during the portion of the stroke of the spindle in which the gear and lap are in engagement and for. releasing the spline guide during the Vportion of the stroke in which the gear and lap are disengaged, and

means operated by the spindle actuating means positively held against turning movements substantially in axial alinement With the spindle, means for reciprocating the spindle to engage and disengage the gear and lap, a spline carried by the spindle, a spline guide rotatably mounted in the housing through which said spline passes, means controlled by the spindle actuating means for holding said spline guide against turning movement during the portion of the stroke of the spindle in which the gear and lap are in engagement and for releasing the spline guide during thegportion of the stroke in which the gear and lap are disengaged, means for indexing the spindle while the spline guide is released, and means for exerting a braking action on the spindle during the indexing operation.

A5. A gear lapping machine comprising a housing, a spindle mounted in the `housing to reciprocate axially, a support, a lap for engagement with the gear to be lapped, said gear and lap being, one in the form of an external gear and the other in the form of an internal gear complemental to the external gear, one attached to the spindle and the other to the support substantially in axial alinementwith the spindle, means for reciprocating the spindle to engage and disengage the lgear and lap, a spline carried by the spindle, a

spline guide rotatably mounted in the housingv through which said spline passes; a clamp mounted on the housing for engagement With the spline guide, means for setting said clamp to hold the spline guide against rotation during the` portion of the stroke of the spindle in which thegear engages the lap and for automatically releasing' the clamp during the portion of the stroke in which the gear and lap are disengaged, and means for indexing the spindle While said clamp is released.

6. A gear lapping machine comprising a'housing, a spindle mounted in the housing to reciprocate axially, a support, a lap for engagement with the gear to be lapped, said gear and lap being, one in the form of an external gear and the other in the form of an internal gear complemental to the external gear, one attached to the spindle and -the other to the support substantially in axial alinement with the spindle, means for reciprocating the spindle to engage, and disengage the gear and lap, a spline carried by the spindle, a spline guide rotatably mounted in the housing through which said spline passes, aI clamp mounted on the housing for engagement with the spline guide, means for setting said clamp to hold the spline guide against rotation during the portion of the stroke of the spindle in which the gear engages the lap and for automatically releasing the clamp during the portion of the stroke in which the gear and lap are disengaged, means for indexing the spindle Whilel said clamp is released, and means acting on the clamp to cause the same to exert a braking action on the spline guide during the indexing operation. i

7. In a machine of the character described, a housing, a spindle mounted to reciprocate axially in the housing, a spline carried by the spindle, a spline guide rotatably mounted lin the housing through which said spline passes, a clamp mounted on the housing in a position to grip said spline guide, means for reciprocating said spindle, means controlled by said spindle actuating means for actuating said clamp to grip the spline guide and hold the same against turning movement during a portion of the stroke of the spindle, and means for imparting a turning movement to the spline guide and spindle during another portion of the stroke of the spindle.

8. In a machine of the character described, a housing, a spindle mounted to reciprocate axially in the housing, a spline carried by the spindle, a spline guide rotatably mounted in the housing through which said spline passes, a clamp mounted on the Ahousing in a position to grip said spline guide, means for reciprocating'said spindle, means for intermittently actuating said clamp to grip the spline guide and hold the same against turning movements, and means for imparting intermittent turning movements to the spline guide and spindle in the intervals in which the clamp is released.

9. In a machine of the character described, a housing, a spindle mounted to reciprocate axially in the housing, a spline carried by the spindle, a spline guide rotatably mounted in the housing through which said spline passes, a. clamp mounted on the housing in a position to grip said spline guide, means for reciprocating said spindle, means controlled by said spindle actuating means for actuating said clamp to grip the spline guide and hold the same against turning movement during a portion of the stroke of the spindle, means for imparting a turning movement to the spline guide and spindle during another portion of the stroke of the spindle, and a spring acting on said clamp to cause the same to exert a braking action on the spline guide while turning movements are being imparted thereto.

10. In a machine of the character described,

a housing, a spindle mounted to reciprocate axially in the housing, a spline carried by the spindle, a spline guide rotatably mounted in the housing through which said spline passes, a clamp mounted on the housing in a position to grip said spline guide, means for reciprocating said spindle, means controlled by said spindle actuating means for actuating said clamp to grip the spline guide and hold the same against turning movement during a portion of the stroke of the spindle, means for imparting a turning movement to the spline guide and spindle during another portion of the stroke of the spindle, a. spring acting on said clamp to cause the same to exert a braking action on the spline guide while turning movements are being imparted thereto, and means for regulating the pressure exerted by lsaid spring on the clamp.

l1. In a machine of the character described, a housing, a spindle mounted to reciprocate axially in the housing, a spline carried by the spindle, a spline guide rotatably mounted in the housing through which said spline passes, a clamp mounted on the housing in a position to grip said spline guide, a crank shaft, means connecting the crank shaft to\the spindle to reciprocate the same, a cam on said shaft, means operated by said cam for intermittently actuating said clamp togrip the spline guide, and -means for imparting turning movements to the spline guide in the intervals between actuation of said clamp.

12. In a. machine of the character described, a housing, a spindle mounted to reciprocate axially in the housing, a spline carried by the spindle, a spline guide rotatably mounted in the housing through Whichsaid spline passes, a clamp mounted on the housing in a position to grip said spline guide, a crank shaft, means connecting the crank 'shaft tothe spindle to reciprocate the same, a

cam on said shaft,` means operatedby said cam for intermittently actuating said clamp to grip the spline guide, means for imparting turning movements to the spline guide in the intervals between actuation of said clamp, and a spring acting on said clamp to cause the same to exert a braking actionfon the spline guide during turning movements thereof.

13. In` a machine of the character described, a housing, a spindle mounted to reciprocate axially in the housing, means for reciprocating the spindle, a spline carried by the spindle, a spline guide through which said spline passes rotatably mounted in the housing, said spline guide being held against axial movement with respect to the housing, and actuating means for intermittently imparting rotative movements to the spline guide and for positively holding said spline guide against rotative movements during the intervals between the actuation thereof.

14. A gear lapping machine comprising a housing, a spindle mounted in the housing for axial reciprocating and rotative movements, a support, a lap complemental to the gear to be lapped, the gear and lap being gear shaped members, one an external gear and the other an internal gear complemental thereto, means for rigidly securing one of said gear shaped members to said support substantially in axial alinement therewith, means for attaching the other of said gear shaped menibers to the spindle and for rigidly holding the latter member against rotative movements with respect to the spindle and yieldably holding the same against lateral movements with respect to the spindle, means for reciprocating the spindle to engage and disengage the gear and lap, a spline carried by the spindle, a spline guide through which the spline extends rotatably mounted in the housing, means for imparting rotative movements to the spline guide while the lap and gear are disengaged to bring different 'teeth of the gear and lap into engaging position, and means for positively holding the spline 'guide against rotative movements during engagement of the gear and lap.

15. In a machine of the character described, a housing, a spindle mounted in the housing, an intermittent wormgearing comprising a worm having a thread with parallel helical portions and parallel circular portions joining the ends of the helicalportions, a gear continuously meshing with said worm and intermittently driven thereby, means for driving said worm, and gearing interposed between said gear and spindle for impartingintermittent rotative movements to said spindle.

16. In amachine of the character described, a housing, a spindle mounted in the housing, an intermittent Worm gearing comprising a worm having a thread with parallel helical portions and parallel circular portions joining the ends of the helical portions, a composite gear continuously meshing with said worm and having teeth provided With helical faces to mesh with the helical portions of the worm thread and with straight faces to mesh with the circular portions of the thread, gearing including a spur gear coaxial'with said composite gear and rotating therewith for driving said spindle from said composite gear.

17. In amachine of the character described, a housing, a spindle mounted in the housing, an intermittent'worm gearing comprising a worm having a thread with parallel helical portions and parallel circular portions joining the ends of the helical portions, a gear meshing with said worm and intermittently driven thereby, means for driving said worm and gearing interposed between said lgear and spindle for imparting intermittent IQ- meagre tative movements to said Spindle, said gearing including adjustable .and interchangeable gears for changing the gear ratio betweensaid composite gearand'spindle.

18. In a machine of the character described, a housing, an axially reciprocating spindle mounted in the housing, a spline carried by the spindle, a spline guide through which said spline passes rotatably mounted in the housing, means fcrlreciprocating said spindle, an intermittent worm gearing comprising a worm having a thread. with parallel helical portions and parallel circular p0rtions joining the ends of the Helical portions, a gear meshing with said worm and intermittently driven thereby, means for driving said worm and` gearing interposed between said gear and Spline guide for imparting intermittent rotative movements to said spindle.

19. In a machine of the character described, a housing, an axially reciprocating spindle mounted in the housing, a spline carried by the spindle, a spline guide through which said spline passes rotatably mounted in the housing, means for reciprocating said spindle, an intermittent worm gearing comprising a worm having a thread with Darallel helical portions and parallel circular portions joining the ends of the helical portions, a gear meshing with said worm and intermittently driven thereby, means for. driving said worm and gearing interposed between said gear and splinek guide for imparting intermittent rotative movements to said spindle, said gearing including adjustable and interchangeable gears for changing the gear ratio between the composite gear and spline guide.

20. In a gear lapping machine,v a housing, a spindlemounted in the housing and adapted t0 supporta gear to be lapped, a spline carried by the shaft, a spline guide rotatably mounted in the housing through which the spindle passes, a gear fixed to the spline guide, a second gear having an equal number of teeth meshing with the gear on the spline guide, a third gear detachably secured to the shaft of the second gear land having the same number of teeth as the gear to `be lapped,

Va fourth 'gear meshing with. the third gear and mounted for adjustment toward and from the axis thereof, a fifth gear meshing with the fourth gear, a worm gear on the shaft of the fifth gear and rotatable therewith, the worm gear having the same number of teeth as the fth gear, a Worm having a thread with helical and circular portions for turning the worm gear one tooth during a portion of the revolution of the worm and for holding the worm gear against turning movements during the remainder of the rotation or the worm, 'and means for driving the worm.

21. In a gear lapping machine, a housing, a spindle mounted in the housing and adapted to support a gear to be lapped, a spline carried by the shaft, a spline guide rotatably mounted in the housing through which the spindle passes, means comprising an intermittent worm gearing and gearing connectingthe worm gearing to the spline guide for intermittently imparting rotative movements to the spline guide and'spindle, a clamp mounted on the housing in position to gripv said spline guide, and means for actuating the clamp to grip the spline guide and hold the same against ,y rotary movements during the intervals between actuaticns thereof.

22. In a gear lapping machine, a housing, a spindle mounted in thev housing and adapted to support a gear to be lapped, a spline carried by the shaft, a. spline guide rotatably mounted in the housing through which the spindle passes, means comprising an intermittent Worm gearing and gearing connecting the worm gearing to the spline guide for intermittently imparting rotative movements to the spline guide and spindle, a clamp mounted on the housing in position to grip said spline guide, means for actuating the clamp to grip the spline guide and hold the same against rotary movements during the intervals between actuations thereof, and yielding means acting on the clamp to cause the same to exert a braking action on the spline guide during the rotative movements thereof.

23. AIn a machine of the character described, a housing, a spindle mounted to reciprocate in the housing, means for reciprocating the spindle, means for driving said spindle reciprocating means, a clutch having a shiftable element for connecting and disconnecting said driving and spindle reciprocating means, a shifter for actuating said shiftable clutch element, a spring acting on said shifter in a direction to release the clutch, means for preventing movement of said clutch element to releasing position except when said spindle is in a predetermined position, and manually releasable latching means for holding said shifter in clutch engaging position.

24. In a machine of the character described, a

housing, a spindle mountedA to reciprocate in the housing, means for reciprocating the spindle, means for driving said spindle reciprocating means, a clutch having a shiftable element for connecting and disconnecting said driving and spindle reciprocating means, a shifter for actuating said shiftable clutch element, a spring acting on said shifter in a direction to release the clutch, means for preventing movement of said clutch element to releasing position except when said spindle is in a predetermined position, manually releasable latching means for holding said shifter in clutch engaging position, and a fixed frictional brake member mounted on the housing against which said clutch member is pressed by said spring when shifted to releasing position.

25. In a machine of the character described, a housing, a spindle mounted to reciprocate inthe housing, means for reciprocating the spindle, means for driving the said spindle reciprocating means, a clutch having a shiftable element for connecting and disconnecting said driving and spindle reciprocating means, a shifter for actuating said shiftable clutch element, a spring acting on said shifter in a direction toy release the clutch, means for preventing movement of said clutch element to releasing position except when said spindle is in a predetermined position, manually 'releasable latching means for holding said shifter in clutch engaging position, and manually operable means for moving said clutch shifter to clutch engaging position.

26. In a machine of the character described, a housing, aspindle mounted to reciprocate in the housing, means for reciprocating the spindle, means for driving said spindle reciprocating means, a clutch having a shiftable element for connecting and disconnecting said driving and spindle reciprocating means, a shifter for actuating said shiftable clutch element, a spring acting on said shifter in a direction to release the clutch, means for preventing movement ,of said clutch element to releasing position except when said spindleis in a predetermined position, latching means for holding said shifter in clutch engaging position, manually operable means for releasing said latching means, and manually operable means for moving said clutch shifter to clutch engaging position.

27'. In a machine of the character described, a housing, a spindle mounted to reciprocate in the housing, means for reciprocating the spindle, means for drivingv said spindle reciprocating means, a clutch having a shiftable element for connecting Aand disconnecting said driving and spindle reciprocating means, a shifter for actuat` ing said shiftable clutch element, a spring acting on said shifter in a direction to release the clutch, means for preventing movement of said clutch element to releasing position except when said spindle is in a predetermined position, latching means for holding said shifter in clutch engaging position, and means operable after a predetermined number of reciprocations of the spindle for releasing `said latching means.

28. In a machine of the character described, a housing, a spindle mounted to reciprocate in the housing, means for reciprocating, the spindle, means for driving said spindle reciprocating means including a clutch having a shiftable element forv connecting and disconnecting said spindle reciprocating and driving means, means for holding said clutch element against movement and for releasing the same when the spindle is in a predetermined position, a member slidably mounted in the housing and connected to said movable clutch element to shift the same, said member having spaced shoulders thereon, a spring acting on said member in a direction to release the clutch, a pair of latches engageable with the spaced shoulders on -said slidable member, said latches being spaced apart farther thanv said shoulders whereby one is normally spaced from-its shoulder, manually operable means' for simultaneously moving said latches to releasing position, and means operated by said driving means for successively releasing said latches after a predetermined number -of reciprocations of said spindle.

v29. In a machine of the character described, a housing, a spindle mounted to reciprocate in the housing, means lfor reciprocating the spindle, means for driving said spindle reciprocating means including a clutch having a shiftable element for connecting and disconnecting said spindle reciprocating and driving means, means for holding said clutch element against movement and for releasing the same when the spindle is in a predetermined position, a member slidably mounted in the housing and connected to said movable clutch element yto shift the same, said member having spaced shoulders thereon, a spring acting on said member in a direction to release the clutch, a pair of latches engageable With the spaced shoulders on said'slidable member, said latches being spaced apart farther than said shoulders, whereby one is normally spaced from its shoulder, manually operable means for simultaneously moving said latches to releasing position, and means for releasing the latches comprising a rotatable trip member having means for successively engaging said latches and moving the same to releasing position and a gear train including adjustable and change gears connecting said trip member to said driving means.

30. In a gear lapping machine, a housing, a spindle mounted to reciprocate in the housing, a gear holding arborhaving means for rigidly securing a gear to be lapped thereto, a key carried by the arbor, a clamp carried by the spindle at one end, said clamp comprising a saddle forming a seat engageable with one side of said arbor and vhaving a socket to receive the key of the arbor,

4 gear holding arbor having means for rigidly securing'a gear to be lapped thereto, a key carried by 4 the arbor, a clamp carried by the spindle at one end, said clamp comprising a V-shaped saddle forming a seat engageable with one side of said arbor' to aline the same axially with the spindle and having a socket to receive the key of the arbor, and a releasable clamping member having means for yieldably pressing said arbor against said saddle.

32. In a gear lapping machine, a housing, a

vertical spindle mounted to reciprocate inthe,

housing, means for detachably fastening a gear to the lower end of the spindle, a lap support on the housing, a lap in the form of an elongated internal gear complemental to the gear to be lappedV rigidly secured to said support substantially in axial alinement with said spindle, a funnel detachably mounted on the top edge of said lap, the small end of the funnel having an.

internal diameter greater than the diameter of said gear, and means for pumping a liquid containing abrasive material and deliveringthe same into said funnel.

33. In a gear lapping machine, a housing, a vertical spindle mounted to reciprocate in the housing, means for detachably fastening a gear to the lower end of the spindle, a lap support on the housing, a lap in the form of an elongated internal gear complemental to the gear to be lapped rigidly secured to said support substantially in axial alinement with said spindle, a funnel detachably mounted on the top edge of said lap, the small end of the funnel having an internal diameter greater than the 'diameter of said gear, means for pumping liquid containing abrasive material and delivering the same into said funnel, and means for collecting the liquid flowing from the lap and returning the same to the pumping means.

34. In a gear lapping machine, a housing, a vertical spindle mounted to reciprocate in the v housing, meansfor detachably fastening a gear to the lower end of the spindle, a lap support on the housing, a lap in the form of an elongated internal gear complemental to the gear to be lapped rigidly secured to said support substantially in axial alinement with said spindle, a funnel detachably mounted on the top edge of said lap, the small end of the funnel having an internal diameter greater than the diameter of said gear, said funnel being composed of upper and lower separable sections, whereby the lower section may be changed for different sized laps, and means for pumping'a liquid containing abrasive material and delivering the same into said funnel.

headers 35. A gear lapping machine comprising a 1 housing, a spindle mounted in the housing to reciprocate axially, a support mounted to turn' `about an axis alined with the spindle axis, a lap complemental to the gear'to be lapped, the gear and lap being gear shaped members, one an external gear and the other an internal gear com.- plemental thereto, one of said members being attached to the spindle and held against rotative movements with respect thereto and the other being xed to the support coaxially therewith, means for reciprocating the spindle, and means for turning said support on its axis to establish abrasive contact between the teeth of the gear and lap comprising a worm gear fixed to the and a hand wheel operatively connected to the worm.

36. A gearv lapping machine comprising a housing, a spindle mounted in the housing to reciprocate axially, a support mountedto turn about an axis alined with the spindle axis, a lap comvplemental to the gear to be lapped, the gear and lap being gear shaped members, one an external helical gear and the other an internal helical gear complemental thereto, one of said members being attached to the spindle and held against rotative movements withrespect thereto and the other being xed to the support coaxially therewith, a helical spline carried by the spindle, a helical spline guide mounted in the housing through which saidspline passes, means for re-l ciprocating said spindle, means for holding said spliney guide against. rotation during engagement or" the gear and lap, and means for turning said support on its axis to establish abrasive contact between the teeth of the gear and lap. 37. A machine for lapping gear shaped articles comprising, a housing, a spindle mounted in the housing for axial reciprocating movements, 'a support axially alined with the spindle, a lap complemental to the gear shaped article to be lapped, the article and lap being gear shaped members, one with external teeth and -the other of complemental form with internal teeth, one of said members being attached to the spindle and held against rotative movements with respect thereto and the other fixed to said support coaxially therewith, means for reciprocating the spindle; and adjusting and holding means for varying the relative angular positions of the spindle and support with respect to their common axis to change the positions of the teeth of the article with respect to the teeth of the lap between which they are interposed and" for positively preventing relative angular movements between the teeth of the article and the teethl of the lap While maintaining the adjusted intermeshing relationshipA during reciprocations of the spindle. ALFRED C. PAGE.

l5 support, a worm meshing with the worm gear 

